Students! I will shortly post a video instruction on how to scan and submit your work. But here's the gist:
Scan your work with the app Genius Scan; it can easily do as many pages as you need
Properly crop your pages and make the filter 'Black and White' (you may need to use pen, but you should practice that anyway)
Optional: name the file (using the name of the assignment); it's easy, just tap the file name (it is automatically the date)
email yourself the scan
move the file from your email into the Google assignment as you would a picture or text doc